Bella Thorne posted makeout pics with her best friend Bella Pendergast -- then came out as bisexual -- but that doesn't mean "Bella Squared" is an item.
Sources close to the Bellas tell us ... Thorne is single, and the two are just friends who like to kiss ... sweet.
August was a busy month for Bella ... she broke up with BF Gregg Sulkin and called Bella P her "soulmate" after the makeout pics ... leading people to believe they were dating.
Not the case ... because the other Bella has been in a serious relationship for months with fellow UC Davis student Bram Kolber.
As for Thorne's breakup, we're told it was a buildup of small fights, but it ended smoothly because Sulkin was cool with her keeping the Sherman Oaks home they purchased together earlier this year.